Additives have become necessary in order to improve the lubricity of fuel, which has been subjected
to the processes of lowering the sulphur content.

This is done both by refineries themselves, and through the use of commercial, after market,
specialist additive suppliers.

Due to the superior lubricity inherent in a host of vegetable oils, these began to be introduced into
fuels distributed for use in diesel engines, in order to restore the lubricity levels.

This process continues to repeat, as fuels progress along the path of diesel from low sulphur diesel,
to very low sulphur diesel, to ultra-low sulphur diesel, and the percentages of vegetable oils is
increased each time.

This process is not without its issues, and new problems are found with each change.
The bottom line is that improving the lubricity of any level of fuel is going to improve the fuel,
reduce wear, and save money.

Improved lubricity also saves fuel.